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Entries in /var/log/messages

 
R.O.
Esteemed Contributor

Entries in /var/log/messages

Hi all,

I have a dns server running linux red hat 7.1 and in /var/log/messages are hundreds of entries like this:

Apr 21 15:52:00 server1 named[1162]: client 1xx.xx.xx.xx#1287: no matching view in class 'CLASS256'.

I found in google the following:

"It means you've got a broken client that doesn't construct proper DNS
queries. This client is using an undefined and invalid class number
for its queries (256) instead of IN - class 1 - which is pretty much
the only valid class for DNS queries. You can ignore the message, but
it would be better to get proper DNS software on the client that's
making these faulty requests."

I think these malformed queries are doing by pcs running windows, but i want to know how this issue can be fixed and if it is possible that these queries provoke a performance problem in the dns server.

Thanks and kind regards
"When you look into an abyss, the abyss also looks into you"
5 REPLIES 5
Sergejs Svitnevs
Honored Contributor

Re: Entries in /var/log/messages

Try to change the "logging" Statement Definition in /etc/named.conf

logging {
category "unmatched" { "null"; };
};

Regards,
Sergejs
Sergejs Svitnevs
Honored Contributor

Re: Entries in /var/log/messages

Try to change the "logging" Statement Definition in /etc/named.conf

logging {
category "unmatched" { "null"; };
};

Regards,
Sergejs
Sergejs Svitnevs
Honored Contributor

Re: Entries in /var/log/messages

Try to change the "logging" Statement Definition in /etc/named.conf

logging {
category "unmatched" { "null"; };
};

Regards,
Sergejs
Sergejs Svitnevs
Honored Contributor

Re: Entries in /var/log/messages

Try to change the "logging" Statement Definition in /etc/named.conf

logging {
category "unmatched" { "null"; };
};

Regards,
Sergejs
Bryan Hunter_1
Occasional Contributor

Re: Entries in /var/log/messages

I have traced the invalid classes to requests for WWW.N3T.COM.BR. These are from the Opasoft (Opaserv) worm virus. I specifically observed CLASS256 & CLASS29540 requesting WWW.N3T.COM.BR from an Opasoft (Opaserv) worm virus (Brasil variant?) infected machine.